Oh god, 5 Kg stones? Are you serious?
The PT requirement would have to be 5 at least, and DAAAMN those would drop quickly.
Anyways: No, 2hing them is not possible as the throwing animation is a 1h throw animation, unless you want to make and submit a 2handed throwing animation for a single item (that you also would need to model)
+ the dev team would have to actually accept them into crpg. Good luck with that!